1,721,293 research outputs found
Mantle to surface gas triggers of magmatic activity at Erebus volcano, Antarctica
No full textIntraplate volcanoes are associated with extensional tectonics, mantle upwelling and high heat flow. Erupted magmas
have an alkaline nature and are rich in volatiles, especially CO2, that are inherited from fluid-rich magmatic
sources in the mantle. Localized alkaline centers emit gas fluxes that exceed what can be sustained by the rates
of magma erupted. At Mount Erebus this dichotomy is evidenced by open-path Fourier transform infrared (FTIR)
spectroscopy of gases released from the lava lake. Different gas signatures are associated with explosive and nonexplosive
gas emissions, representative of volatile contents and redox conditions that identify the overlap between
shallow and deep degassing sources. We show that this multiple signature of magma degassing provides a unique
probe for magma differentiation and transfer of CO2-rich oxidized fluids from lithospheric roots up to the surface,
and show how these processes operate in time and space. Magma deeper than 4 km equilibrates under vapour
buffered conditions, whereas shallower magmas allow deep, CO2-rich fluids to accumulate and prior to release
either via open-system degassing conditions and reduced oxidation states, or as volatile-enriched, phonolitic blobs
that preserve the deep oxidized signature, and ascend as a closed-system to explode at the surface during Strombolian
phases
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Perspectives on the active volcanoes of China
Get PDFChina has a rich record of Holocene volcanism that is relatively little known outside the country. It is encountered in large stratovolcanoes in the NE, linked to subduction of the Pacific plate (e.g. Changbaishan), in smaller volcanoes on the Tibetan margin, associated with the collision of India and Eurasia (e.g. Tengchong, Ashishan), and in more isolated centres, possibly resulting from mantle upwelling (e.g. volcanoes in Hainan island). This makes China a natural laboratory for studies of intraplate volcanism, and significant progress in understanding its nature and origins has been made over the past quarter century. Here, we introduce the first publication in English to provide a comprehensive survey of the state of knowledge and research highlights. Accordingly, we provide an overview of the dynamics, geology, geochemistry, volcanic histories and geophysical studies of 14 volcanic areas associated with the Holocene documented thus far. The special publication represents a benchmark reference on the topic but, as importantly, we hope that it will stimulate new, international collaborations aimed at deepening our understanding of the origins, history, hazards and associated risks of China's volcanoes
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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